A man lives on the 10th floor of a building. Every morning he takes the elevator to the ground floor to go to work. Upon returning from work he goes up always to floor 7th in the elevator. Then he goes upstairs the 3 remaining floors.
The man is very short so he has no problem to press the button on the ground floor but he does not reach the 10th floor button. The maximum he reaches is up to the 7th floor button.